The "game" of minecraft is when you play in survival mode. You have to build a fort during the day to survive all the monsters at night. You can craft all kinds of tools and explore all sorts of different stuff. It is this exploring and crafting and building that is fun. All the pictures of people making computers and stuff is done in like "wizard" or "god" mode where you can just create blocks willy nilly without having to do any mining/exploring/crafting.